关键词: 深拖曳地震系统, 阵列几何形态反演, 遗传算法, 天然气水合物

Abstract: An advanced technique to accurately invert the array geometry of the high resolution deep-towed multichannel seismic system DTAGS (deep-towed acoustics and geophysics system) was developed for each shot based on previous studies. This technique used picked arrival times of direct wave and sea-surface reflecting wave as constrain conditions, brought the systematic error of the array nodes’ depths and the fluctuation of the seawater velocity into the inversion process, and employed genetic algorithm to simultaneously invert the whole controlling parameters and to achieve globally optimistic DTAGS array geometry. In the application of exploring marine gas hydrate at the North Cascadia margin, the advanced array geometry inversion technique improved the DTAGS imaging quality dramatically, and thus provided full and accurate details of gas-hydrate-related sedimentary and structural features.

Key words: deep-towed seismic system, array geometry inversion, genetic algorithm, gas hydrate